Commercial garlic cultivars are propagated only vegetatively. Since viral infection is sheltered in all plant organs, it is transmitted from one generation to another. Bolting varieties of garlic often produce small bulbils in the inflorescence that can be used for propagation. We studied morphological and histological aspects of bulbil differentiation and virus transmission from the mother plant to the next generation. During inflorescence development, flowers differentiate first and then bulbils initiate between flower buds. Lignified vascular cells transport water and nutrients to the differentiating bulbils, together with virus particles that are translocated from the older organs. The two most dangerous potyviruses for garlic, OYDV and LYSV, were detected at the very early stages of garlic inflorescence differentiation, when the vascular system only began to differentiate, and later massive systemic viral infection of the mature bulbils was identified. In spite of common assumption that bulbils produce virus-free regenerants in tissue culture, RT-PCR analysis clearly shows the presence of both viruses in the regenerants originating from young inflorescences. It is concluded that without special means for virus eradication, in vitro propagation from garlic inflorescence or bulbils has no advantage in obtaining virus free propagation material.

商业大蒜品种仅通过营养繁殖。由于病毒感染被所有植物器官所掩盖，因此它可以从一代传给另一一代。大蒜的栓接品种通常在花序中产生小的鳞茎，可用于繁殖。我们研究了球茎分化和病毒从母本植物向下一代传播的形态学和组织学方面。在花序发育过程中，花朵先分化，然后在花蕾之间萌生鳞茎。木质素化的血管细胞将水和营养物质以及从较早器官转移过来的病毒颗粒运送到分化的胚芽中。在大蒜花序分化的早期，就检测到两种最危险的大蒜锅病毒OYDV和LYSV，当血管系统才开始分化，后来鉴定出成熟球茎的大规模全身性病毒感染。尽管人们普遍认为球茎在组织培养物中会产生无病毒的再生子，但RT-PCR分析清楚地表明，两种病毒都存在于源自年轻花序的再生子中。结论是，如果没有特殊的病毒消灭手段，从大蒜花序或鳞茎的体外繁殖在获得不含病毒的繁殖材料方面没有优势。